Molecular clock hypothesis

The molecular clock hypothesis suggests that genetic mutations accumulate in DNA at a relatively constant rate over time. Because of this, scientists can compare the DNA differences between two species to estimate how long ago they shared a common ancestor. Essentially, if two species have many differences, they diverged longer ago; if few, they diverged more recently. This approach helps scientists understand evolutionary timelines by assuming consistent mutation rates, although these rates can vary among different organisms and genes.